JP2001093745A - Laminated chip component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated chip component, which can prevent defects in connection and disconnection between a terminal electrode and a lead-out electrode by suppressing degeneration due to vaporization and diffusion at baking of the electrode material of the lead-out electrode of a coil-forming conductor. SOLUTION: Magnetic body layers 1a to 1g and coil-forming conductors 2a to 2f are laminated and sintered, to constitute an inductor or a laminated chip component which includes an inductor. Terminal electrodes 6a and 6b, provided on the external surface of the laminated chip component, are connected to lead-out electrode parts 3a and 3b of the coil-forming conductors. Dummy electrodes 5a to 5b are formed in the laminated sinter, so that they are partially exposed in the exposed surfaces of the lead-out electrode parts 3a and 3b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated chip component in which an inductor is formed by laminating and sintering a magnetic layer and a coil-forming conductor, or in which another element such as a capacitor is built in with the inductor.

[0002]

2. Description of the Related Art As electronic components are increasingly mounted on surfaces, multilayer chip inductors and multilayer chip filters as multilayer chip components are widely used. As shown in the layer structure diagram of FIG. 2A, most of such laminated chip components have a plurality of coil forming conductors 2a to 2f formed on a plurality of electrically insulating magnetic layers 1b to 1g. Magnetic layer 1 on the surface
a is provided, and the coil forming conductors 2a to 2f are connected by through holes 4a to 4e at their respective ends, or printed or laminated such that the ends of the coil forming conductors 2a to 2f overlap each other. Laminated and compressed.

The magnetic layers 1a to 1g are generally made of a Ni--Cu--Zn ferrite which can be fired at a low temperature. These ferrite magnetic powders are made of a binder such as methylcellulose, butyral resin or the like. Is obtained by printing or rolling the paste kneaded in the above into a sheet.

The coil forming conductors 2a to 2f are made of Ag.
Alternatively, an Ag alloy such as Ag-Pd is used. And
The coil forming conductors 2a to 2f are formed by forming a powder of a heat-resistant metal such as Ag or an Ag alloy into a paste, and printing the paste in a predetermined pattern. After crimping, it is cut into individual chips and then fired. The cutting is performed such that the extraction electrode portions 3a and 3b at both ends of the coil forming conductors 2a to 2f are exposed to the outer surface, as shown in the chip end view of FIG.
After firing the chip, as shown in FIGS. 2C and 2D, the terminal electrodes 6 connected to the extraction electrode portions 3a and 3b
The conductive paste is provided by baking and plating.

[0005]

The above-mentioned coil forming conductor 2
It is well known that Ag has lower resistivity than Ag alloy in a to 2f. However, when this Ag electrode is used, the shrinkage is higher than that of the Ag alloy, and since the baking is performed at a temperature close to the melting point, the evaporation of Ag tends to occur during the baking, and FIG. 2 (C) and FIG. As shown, the extraction electrode portions 3a and 3b are not sufficiently exposed on the surface of the laminate, and the gap portions 7
Occurs, that is, degeneration occurs, and the extraction electrode portions 3a and 3b cannot be sufficiently electrically connected to the terminal electrode 6, which may result in poor connection or disconnection.

In order to solve such a problem, conventionally, the extraction electrodes 3a and 3b are widened to reduce the electric resistance of the connection, and as disclosed in Japanese Patent Publication No. 3-63205, A structure is adopted in which the extraction electrode portions 3a and 3b are thickened so that the electrical resistance of the connection portion is as low as possible. In Japanese Utility Model Publication No. 4-32733, 1
A plurality of extraction electrode portions are provided for one extraction portion, so that the resistance of the connection portion is reduced as much as possible.

However, in the structure in which the width of the extraction electrode portions 3a and 3b is widened, there is a limit to the width to be widened depending on the shape of the product, and the thickness obtained by one printing is as thin as several μm to several tens μm. When the evaporation rate is high, the effect of reducing the voids 7 is reduced.

Further, as disclosed in Japanese Patent Publication No. 3-63205, in the structure in which the thickness of the extraction electrode portions 3a and 3b is increased, a structure in which a large amount of Ag is concentrated at one location is obtained. The electrode material of the electrode portions 3a and 3b (A
g) and the magnetic material layer, the extraction electrode portion 3
The possibility of cracking is higher than a and 3b.

Further, as disclosed in Japanese Utility Model Publication No. 4-32733, in a structure in which a plurality of extraction electrode portions 3a and 3b are provided, the inductance value depends on which extraction electrode portion the terminal electrode 6 is connected to. The difference causes a variation in characteristics.

SUMMARY OF THE INVENTION In view of the above problems, the present invention suppresses degeneration due to evaporation and diffusion of the electrode material in the extraction electrode portion of the coil-forming conductor at the time of firing, thereby preventing poor connection between the terminal electrode and the extraction electrode portion. An object of the present invention is to provide a laminated chip component having a structure capable of preventing disconnection.

[0011]

According to the present invention, there is provided a laminated chip component in which a magnetic layer and a coil-forming conductor are laminated and sintered, and a lead-out electrode portion of the built-in coil-forming conductor is exposed on the outer surface of the laminated sintered body. A laminated chip component including an inductor or an inductor provided with a terminal electrode connected to the extraction electrode portion on an outer surface of the laminated sintered body, wherein a dummy electrode is partially disposed on an exposed surface of the extraction electrode portion. It is characterized in that it is formed in a laminated sintered body so as to be exposed.

As described above, if the dummy electrode exposed on the outer surface of the laminated chip component is provided, the vapor of the metal electrode material is generated from the dummy electrode during firing, and the vapor is generated by the generated vapor of the metal material. The amount of vapor of the electrode material in the atmosphere around the electrode part increases, and the evaporation of the metal material from the extraction electrode part is suppressed. For this reason, the contraction of the extraction electrode portion is suppressed,
Poor connection and disconnection with the terminal electrode can be prevented.

According to a second aspect of the present invention, in the first aspect, the dummy electrode is provided along an exposed surface.

Thus, by providing the dummy electrodes along the exposed surfaces of the chip components, it is possible to secure a wide facing area to the outside, that is, a wide evaporation surface during firing, with a small dummy electrode area.

[0015]

1 shows an embodiment of a laminated chip component according to the present invention. FIG.
(B) is an end view of a chip before forming a terminal electrode, (C) is a perspective view of a product, and (D) is a cross-sectional view of the product.

As shown in FIG. 1A, a multilayer chip component is composed of a plurality of magnetic layers 1b to 1g made of a paste or a sheet of Ni-Cu-Zn ferrite or the like and a plurality of layers made of an Ag or Ag alloy paste. Coil forming conductors 2a-2
f is formed, and a magnetic layer 1a on the surface is further provided.
The coil forming conductors 2a to 2f are overlapped so as to be connected by through holes 4a to 4e at their respective ends. In the case of the printing method, the coil forming conductors 2a to 2f are connected by directly overlapping the ends.

Reference numerals 5a to 5d denote dummy electrodes formed on the magnetic layers 1c to 1f using the same electrode forming material as the coil forming conductors 2a to 2f. These dummy electrodes 5a to 5d
As shown in FIG. 1B, on the cut surface of the laminated material in which the coil-forming conductors 2a to 2f for a plurality of chips are formed and laminated, at positions exposed to the outer surface together with the extraction electrode portions 3a and 3b. Can be

By providing such dummy electrodes 5a to 5d, when the laminated material is cut and baked, the dummy electrodes 5a to 5d can be used.
Since the Ag vapor constituting a to 5d evaporates, the Ag vapor density in the atmosphere around the extraction electrode portions 3a and 3b increases, and the evaporation of Ag in the extraction electrode portions 3a and 3b is suppressed. For this reason, the generation of the voids 7 on the exposed surface of the extraction electrode shown in FIGS. 2C and 2D, that is, the contraction of the exposed surfaces of the extraction electrodes 3a and 3b is suppressed.

For this reason, FIG. 1 after laminating, crimping and cutting the magnetic layers 1a to 1g and the coil forming conductors 2a to 2f.
When the terminal electrodes 6a, 6b are connected to the lead electrode portions 3a, 3b by baking Ag or its alloy paste and plating with another metal on both ends of the laminated sintered body 1 shown in FIG. Poor connection or disconnection between the lead electrode 6b and the extraction electrode portions 3a, 3b can be prevented.

The arrangement structure of the dummy electrodes 5a to 5d is such that the dummy electrodes 5a, 5c
(5b, 5d) is provided in parallel, that is, providing the dummy electrodes 5a to 5d long along the chip cutting surface (that is, the exposed surfaces of the extraction electrode portions 3a and 3b) is performed. 5d, the coil-forming conductors 2a to 2d in the same layer as the dummy electrodes 5a to 5d.
This is preferable for efficiently evaporating the electrode material of the dummy electrode without fear of connection with f.

The dummy electrodes 5a to 5d may be provided not only at one end but also at both ends of the magnetic layers 1c to 1f. Further, dummy electrodes exposed on the side surfaces as well as the end surfaces on which the terminal electrodes 6a and 6b are provided may be added.

The present invention can be applied not only to a case where Ag or an Ag alloy is used as the electrode metal, but also to a case where another metal is used as the electrode material. Further, the present invention is not limited to the case where only the inductor is built in the multilayer chip component,
The present invention can also be applied to a composite component in which an inductor and a capacitor are superimposed.

[0023]

According to the first aspect of the present invention, since the dummy electrode exposed on the outer surface of the multilayer chip component is provided, the vapor of the metal electrode material is generated from the dummy electrode during firing, and the generated metal material is generated. Since the evaporation of the metal material from the extraction electrode portion is suppressed by the vapor, the contraction of the extraction electrode portion is suppressed, and poor connection with the terminal electrode and disconnection can be prevented.

Further, since it is not necessary to increase the thickness of the extraction electrode portion, there is no risk of cracks or the like.

Further, since the dummy electrode is an electrode which is not connected to other portions, it does not directly affect the characteristics and does not cause a variation in the characteristics.

According to the second aspect, since the dummy electrode is provided along the exposed surface of the extraction electrode portion, the area of the narrow dummy electrode does not cause a problem such as connection with the coil forming conductor or the like, so that the electrode material can be formed. The vapor can be efficiently evaporated.

[Brief description of the drawings]

FIG. 1A is a laminated structural view showing an embodiment of a laminated chip component according to the present invention, FIG. 1B is an end view of a chip before forming terminal electrodes thereof, FIG. 1C is a perspective view of the product thereof, (D)
Is a sectional view of the product.

FIG. 2A is a laminated structural view showing a conventional laminated chip component, FIG. 2B is an end view of the chip before forming terminal electrodes thereof,
(C) is a sectional view showing a connecting portion between the extraction electrode portion and the terminal electrode, and (D) is an EE sectional view of (C).

[Explanation of symbols]

1: laminated sintered body, 1a to 1g: magnetic layer, 2a to 2f:
Coil forming conductors, 3a, 3b: lead electrode portions, 4: through holes, 5a to 5d: dummy electrodes, 6a, 6b: terminal electrodes

Claims (2)

[Claims] A magnetic layer and a coil-forming conductor laminated and sintered to expose an extraction electrode portion of a built-in coil-forming conductor on an outer surface of the laminated sintered body; And a laminated chip component including an inductor provided with a terminal electrode connected to the portion, wherein the dummy electrode is formed in the laminated sintered body such that a part of the dummy electrode is exposed on the exposed surface of the extraction electrode portion. A laminated chip component characterized by the above-mentioned. 2. The multilayer chip component according to claim 1, wherein the dummy electrode is provided along an exposed surface.